Zylstra's work shows that, if we are going to try to analyze essence in terms of necessity and intrinsicality and deliver the goods on Fine's celebrated Socrates/{Socrates} example (Socrates does not belong essentially to {Socrates}, but {Socrates} essentially contains Socrates), we had better understand intrinsicality as term-relative, at least in the case of relations. That is, we can't just say that some relations are intrinsic and others are extrinsic and that's it - rather, some two-place relations are, so to speak, intrinsic on one side but extrinsic on the other.
But can we really explicate such a concept of intrinsicality? Or is this really just going to be the concept of essence which we end up explicating? If we can do the job, then we should get something that, when supplemented with necessity, yields the notion of essence. This suggests that we should be able to find contingent cases of such asymmetric intrinsicality. And so that now seems to be the big question, if we're wondering whether essence should be accounted for in terms of necessity and something else, or the other way around. (Or at least whether intrinsicality should be involved if we pursue the first strategy.)
Thinking about parts of things, where those things could nevertheless have had different parts, may be one way of looking. For instance, perhaps 'My laptop contains the chip C' provides such an example. If the chip is intrinsic to the laptop, then we can say that the laptop intrinsically contains the chip, but that the chip is not intrinsically inside the laptop. But the laptop could have had another chip or perhaps no chip in that place, so it does not contain the chip necessarily.
I wonder how solid and convincing this sort of example is, though, and I wonder if there are other sorts available.
Showing posts with label modality. Show all posts
Showing posts with label modality. Show all posts
Monday, 11 December 2017
Saturday, 9 December 2017
Sticking Up for 'Essence = Necessity + Intrinsicality' in the Face of Zylstra's Argument
Followup: Contingent Examples of Term-Relative Intrinsicality?
UPDATE 11/12/2017: The more I think about Zylstra's argument, the more I think I've been overly critical, and not sufficiently open to changing my views. I have moderated some of the worst excesses by editing the below a little bit. I continue to think about the lessons which we should draw from Zylstra's argument, and may come back to the matter in a future post. One thing which has just begun to bother me is that, if we try to take the lesson to show that we'd better make intrinsicality term-relative when it comes to relations, is that the stuff which comes to mind when trying to explicate the resulting notion of "intrinsicality" - I found myself thinking things like 'x bears R to y intrinsically if part of what it is to be x is to be R-related to y' - just ends up sounding like a characterisation of essence; the necessity-ish bit seems to come of its own accord. So maybe there are grounds here for serious doubt about the overall E = N + I approach to essence.
An interesting new paper by Justin Zylstra attempts to cast doubt on the project of analyzing essence in terms of necessity plus something else. As Fine famously pointed out, it is plausible that the set {Soctrates} essentially contains Socrates but that Socrates does not essentially belong to {Socrates}. Being a member of that set does not have enough to do with Socrates as he is in himself, we might say, to count as an essential property of Socrates. Nevertheless, Socrates necessarily belongs to {Socrates}; in no possible world do we find Socrates but not the set containing him.
So essential properties aren't just the necessarily-possessed properties, or so it seems. Fine makes the further proposal that we give up trying to analyze essence in terms of necessity and instead go the other way around. But others have accepted that the essential properties aren't just the necessarily-possessed ones, but sought to supplement the analysis of essence in terms of necessity. I am sympathetic to this approach, and particularly to the idea - prominently defended by Denby - that essence = necessity + intrinsicality. Let's call this the E = N + I approach.
(Denby, it is important to note, favours an account of intrinsicality on which the property of containing Soctrates is not intrinsic, but extrinsic, to {Socrates}. This leads him to push back against the prima facie plausible Finean thesis that containing Socrates is essential to {Socrates}. In my view, this was a mistake on Denby's part, and we should instead try to understand 'intrinsic' in such a way that it does come out true that the property of containing Socrates is intrinsic to {Socrates}.)
You can imagine my interest in Zylstra's paper, which is supposed to cast serious doubt on this approach. Here I want to explain why I think it does no such thing. I won't reconstruct Zylstra's detailed and technically sophisticated argument in full. To fully assess what I'm saying, in particular to verify that I speak the truth about what Zylstra does in his paper, you'd have to look at the paper.
To understand why Zylstra's argument goes as wrong as I think it does, it helps to note that he aims his criticisms more generally at any attempt to supplement a necessity-based analysis of essence so that it delivers the goods on Fine's celebrated examples, provided it is of a certain general form. He intends this form to cover the E = N + I approach. The trouble is, it is very easy to formulate a version of that approach which does not take general form in question.
The central problem with Zylstra's handling of the E = N + I approach is that he considers only Denby's version, which proceeds as if the relevant notion of intrinsicality can be treated as a sentential operator. It is intrinsic that p. But no friend of the E = N + I approach should want to do that.
The whole point of bringing in intrinsicality, I would have thought, is that it is plausibly intrinsic to {Socrates} that it contains Socrates, but not intrinsic to Socrates that he is contained by {Socrates}. But if we represent our idea of intrinsicality as a sentential operator, all we can say is:
It is intrinsic that Socrates is a member of {Socrates}.
or
It is intrinsic that {Socrates} contains Socrates.
or whatever.
Now, this doesn't really even make sense without explanation, but putting that aside, and assuming that such claims will either be true or be false, Zylstra is able to show that an analysis of essence in terms of necessity and this weird intrinsicality sentential operator can't deliver the goods.
But so what? This just shows that the relevant notion of intrinsicality can't be captured as a sentential operator! Indeed, in his last section, entitled 'A glimmer of hope', Zylstra suggests that instead of supplementing a necessity-based analysis of essence with a notion that can be expressed as a sentential operator, we might be able to use an operator that takes a sentence and a noun phrase and produces a sentence:
I conclude that Zylstra's new paper poses no real threat at all to the E = N + I approach to understanding essence. Rather, the lesson that the friend of the E = N + I approach should draw is that intrinsicality is not to be expressed using a monadic sentential operator. Nor will it do to think of it, in general, as something which relations possess or fail to possess tout court. A relation like the set-membership relation is, so to speak, extrinsic on Socrates’s end but intrinsic on {Socrates}’s end.
In a way, this is really just a criticism about emphasis. Rather than presenting his argument as if it were a serious threat to the E = N + I approach, and then offering a 'glimmer of hope', Zylstra should, in my view, have just presented his argument as showing something instructive about how a friend of the E = N + I should, and should not, try to formulate it.
References
Denby, David A. (2014). Essence and Intrinsicality. In Robert Francescotti (ed.), Companion to Intrinsic Properties. De Gruyter. pp. 87-109.Author-archived version currently available open-access at http://philpapers.org/rec/DENIAE-3.
Fine, Kit (1994). Essence and modality. Philosophical Perspectives 8:1-16.
Zylstra, Justin (forthcoming). Essence, necessity, and definition. Philosophical Studies:1-12. Currently available open-access at the author's Academia.edu page, the URL of which is currently http://vermont.academia.edu/JustinZylstra.
UPDATE 11/12/2017: The more I think about Zylstra's argument, the more I think I've been overly critical, and not sufficiently open to changing my views. I have moderated some of the worst excesses by editing the below a little bit. I continue to think about the lessons which we should draw from Zylstra's argument, and may come back to the matter in a future post. One thing which has just begun to bother me is that, if we try to take the lesson to show that we'd better make intrinsicality term-relative when it comes to relations, is that the stuff which comes to mind when trying to explicate the resulting notion of "intrinsicality" - I found myself thinking things like 'x bears R to y intrinsically if part of what it is to be x is to be R-related to y' - just ends up sounding like a characterisation of essence; the necessity-ish bit seems to come of its own accord. So maybe there are grounds here for serious doubt about the overall E = N + I approach to essence.
An interesting new paper by Justin Zylstra attempts to cast doubt on the project of analyzing essence in terms of necessity plus something else. As Fine famously pointed out, it is plausible that the set {Soctrates} essentially contains Socrates but that Socrates does not essentially belong to {Socrates}. Being a member of that set does not have enough to do with Socrates as he is in himself, we might say, to count as an essential property of Socrates. Nevertheless, Socrates necessarily belongs to {Socrates}; in no possible world do we find Socrates but not the set containing him.
So essential properties aren't just the necessarily-possessed properties, or so it seems. Fine makes the further proposal that we give up trying to analyze essence in terms of necessity and instead go the other way around. But others have accepted that the essential properties aren't just the necessarily-possessed ones, but sought to supplement the analysis of essence in terms of necessity. I am sympathetic to this approach, and particularly to the idea - prominently defended by Denby - that essence = necessity + intrinsicality. Let's call this the E = N + I approach.
(Denby, it is important to note, favours an account of intrinsicality on which the property of containing Soctrates is not intrinsic, but extrinsic, to {Socrates}. This leads him to push back against the prima facie plausible Finean thesis that containing Socrates is essential to {Socrates}. In my view, this was a mistake on Denby's part, and we should instead try to understand 'intrinsic' in such a way that it does come out true that the property of containing Socrates is intrinsic to {Socrates}.)
You can imagine my interest in Zylstra's paper, which is supposed to cast serious doubt on this approach. Here I want to explain why I think it does no such thing. I won't reconstruct Zylstra's detailed and technically sophisticated argument in full. To fully assess what I'm saying, in particular to verify that I speak the truth about what Zylstra does in his paper, you'd have to look at the paper.
To understand why Zylstra's argument goes as wrong as I think it does, it helps to note that he aims his criticisms more generally at any attempt to supplement a necessity-based analysis of essence so that it delivers the goods on Fine's celebrated examples, provided it is of a certain general form. He intends this form to cover the E = N + I approach. The trouble is, it is very easy to formulate a version of that approach which does not take general form in question.
The central problem with Zylstra's handling of the E = N + I approach is that he considers only Denby's version, which proceeds as if the relevant notion of intrinsicality can be treated as a sentential operator. It is intrinsic that p. But no friend of the E = N + I approach should want to do that.
The whole point of bringing in intrinsicality, I would have thought, is that it is plausibly intrinsic to {Socrates} that it contains Socrates, but not intrinsic to Socrates that he is contained by {Socrates}. But if we represent our idea of intrinsicality as a sentential operator, all we can say is:
It is intrinsic that Socrates is a member of {Socrates}.
or
It is intrinsic that {Socrates} contains Socrates.
or whatever.
Now, this doesn't really even make sense without explanation, but putting that aside, and assuming that such claims will either be true or be false, Zylstra is able to show that an analysis of essence in terms of necessity and this weird intrinsicality sentential operator can't deliver the goods.
But so what? This just shows that the relevant notion of intrinsicality can't be captured as a sentential operator! Indeed, in his last section, entitled 'A glimmer of hope', Zylstra suggests that instead of supplementing a necessity-based analysis of essence with a notion that can be expressed as a sentential operator, we might be able to use an operator that takes a sentence and a noun phrase and produces a sentence:
Recall that the Supplemented Necessity Analysis involved an existentially bound variable O that functions syntactically as a monadic sentential operator. But nothing prohibits us from introducing a further type of variable Xt that functions syntactically as a binary term-sentence operator. (Zylstra (forthcoming), Section 5.)Considering as he is all analyses of the relevant, sentential-operator form, rather than just the weird instrinsicality-as-a-sentential-operator instance, he never comes back to consider that maybe the E = N + I approach should be pursued with a binary term-sentence operator. (Another reason for Zylstra's neglecting to do this, perhaps, is that it is Denby's version of the approach that Zylstra considers, and that version - ill-advisedly, as I suggested in a parenthesis near the beginning of this post - fails to deliver the intuitive Finean verdict that containing Socrates is essential to {Socrates}.) But really, that's just the natural view when you think about this. The weird sentential-operator form is just an especially bad version of the E = N + I approach which no one sympathetic to that approach should allow.
I conclude that Zylstra's new paper poses no real threat at all to the E = N + I approach to understanding essence. Rather, the lesson that the friend of the E = N + I approach should draw is that intrinsicality is not to be expressed using a monadic sentential operator. Nor will it do to think of it, in general, as something which relations possess or fail to possess tout court. A relation like the set-membership relation is, so to speak, extrinsic on Socrates’s end but intrinsic on {Socrates}’s end.
In a way, this is really just a criticism about emphasis. Rather than presenting his argument as if it were a serious threat to the E = N + I approach, and then offering a 'glimmer of hope', Zylstra should, in my view, have just presented his argument as showing something instructive about how a friend of the E = N + I should, and should not, try to formulate it.
References
Denby, David A. (2014). Essence and Intrinsicality. In Robert Francescotti (ed.), Companion to Intrinsic Properties. De Gruyter. pp. 87-109.Author-archived version currently available open-access at http://philpapers.org/rec/DENIAE-3.
Fine, Kit (1994). Essence and modality. Philosophical Perspectives 8:1-16.
Zylstra, Justin (forthcoming). Essence, necessity, and definition. Philosophical Studies:1-12. Currently available open-access at the author's Academia.edu page, the URL of which is currently http://vermont.academia.edu/JustinZylstra.
Thursday, 9 November 2017
Two-Dimensional Semantics and Counterfactual Invariance Deciders
For a long time I have wondered, with an uneasy feeling that there was something I couldn't see, about the relationship between two-dimensional semantics and my approach to analysing subjunctive necessity de dicto. As I flagged in the previous post, this has become even more urgent in light of my new, relational account involving the notion of a counterfactual invariance (CI) decider.
I think I've finally made a breakthrough here, and found a clear connection. There is more to say, but here it is briefly.
Recall that my account states that a proposition is necessary (i.e. necessarily true or necessarily false) iff it has a true positive counterfactual invariance (CI) decider.
(P is a positive counterfactual invariance decider for Q iff Q does not vary across genuine counterfactual scenario descriptions for which P is held true.)
A close analogue of this account can be stated in terms of two-dimensional semantics: a proposition Q is necessary iff there is a true proposition P such that for every scenario S in which P is true, Q's two-dimensional intension maps, for all W, <S, W> to the same truth-value.
And I think I can maintain, as CI deciderhood is plausibly a priori tractable and arguably a semantic matter, so too is the question whether, given some propositions P and Q, P is such that for every scenario S in which P is true, Q's two-dimensional intension maps, for all W, <S, W> to the same truth-value.
This makes clear one major way in which my analysis goes beyond the normal two-dimensional account of subjunctive necessity in terms of secondary (or C) intension - and this way can then be translated into two-dimensional terms. And looking at necessity this way, as opposed to with just the usual two-dimensional account of subjunctive necessity, gives us a finer grained picture of the role played by what Kripke called 'a priori philosophical analysis' in our knowledge of necessity. You don't have to know which scenario is actual to know that a proposition is necessary - you just need to know that you're in one of some range of scenarios such that, if they were actual, the proposition would be necessary. And such a range can be characterized by a proposition which you can know a priori to be a CI decider for the necessary proposition in question.
I think I've finally made a breakthrough here, and found a clear connection. There is more to say, but here it is briefly.
Recall that my account states that a proposition is necessary (i.e. necessarily true or necessarily false) iff it has a true positive counterfactual invariance (CI) decider.
(P is a positive counterfactual invariance decider for Q iff Q does not vary across genuine counterfactual scenario descriptions for which P is held true.)
A close analogue of this account can be stated in terms of two-dimensional semantics: a proposition Q is necessary iff there is a true proposition P such that for every scenario S in which P is true, Q's two-dimensional intension maps, for all W, <S, W> to the same truth-value.
And I think I can maintain, as CI deciderhood is plausibly a priori tractable and arguably a semantic matter, so too is the question whether, given some propositions P and Q, P is such that for every scenario S in which P is true, Q's two-dimensional intension maps, for all W, <S, W> to the same truth-value.
This makes clear one major way in which my analysis goes beyond the normal two-dimensional account of subjunctive necessity in terms of secondary (or C) intension - and this way can then be translated into two-dimensional terms. And looking at necessity this way, as opposed to with just the usual two-dimensional account of subjunctive necessity, gives us a finer grained picture of the role played by what Kripke called 'a priori philosophical analysis' in our knowledge of necessity. You don't have to know which scenario is actual to know that a proposition is necessary - you just need to know that you're in one of some range of scenarios such that, if they were actual, the proposition would be necessary. And such a range can be characterized by a proposition which you can know a priori to be a CI decider for the necessary proposition in question.
Monday, 6 November 2017
Old Account May Not Be False After All, But New One Still Better (and New Frontier: Relation to Two-Dimensionalism)
Last Thursday I gave a talk at Sydney University's philosophy department about Kipper's bombshell, my old account of necessity, and my new account involving counterfactual invariance deciders. I was asked many good questions and got a lot out of it.
In preparing the talk, I came to realise that I may have been too quick to assume that 'Air is airy' disproves my old account, according to which a proposition is necessarily true iff it is in the deductive closure of the set of propositions which are both true and inherently counterfactually invariant. Because 'There is nothing more to being air than being airy' is plausibly true and ICI, and it does - at least on a rich enough notion of impication - imply 'Air is airy'.
Now, if that's right, what follows? Are my new ideas about abandoning, in the analysis of necessity, the property of ICI for a relation of deciderhood, to be thrown out? I don't think so. Even if I was pushed towards them by the possibly wrong idea that my old account can't be defended from 'Air is airy', they still seem to give us an account which seems better. The old account now seems clumsy, so to speak. Maybe it can be understood in a way - with a rich notion of implication - so that it doesn't go wrong on 'Air is airy'. But this still seems like a kind of lucky break, and it's not clear to me that there aren't more threatening examples in the offing. The new account, on which a proposition is necessary iff it has a true positive counterfactual invariance decider, seems to reveal the notion's workings more faithfully, and seems less hostage to as-yet-unconsidered examples.
(Also note that, with the new account, you can use 'There's nothing more to being air than being airy' as your decider, but it seems like you can also use something like 'Air has no underlying nature' or 'Air is not a natural kind', and these do not seem to imply 'Air is airy' - they do not seem to contain that information. And since it seems you can plug these into the new account and conclude that 'Air is airy' is necessary, but cannot conclude the same on the same basis with the old account, that the new account is superior here, in enabling us to conclude necessity on a sometimes slenderer basis than we can using the old account.)
In the talk I gave, there were a number of questions and examples suggested which could look like they may disprove my account, but I was able to respond to all of them straightforwardly and to my account's credit. (With some elements of the new account, it's hard to see immediately why they're there and are as they are, but working through some examples clarifies things.) I also fielded a question (thanks to N.J.J. Smith) about how my account goes beyond what we already find in Kripke. There too I was able to give what I think is a satisfactory answer: the account isolates a plausibly a priori tractable, maybe broadly semantic, aspect to necessity. Kripke's work doesn't do this. He says a proposition is necessary if it holds in all the ways things could have been, and one of his main points is that we don't in general know a priori what these ways are. True, he also allows that we know by 'a priori philosophical analysis' (this occurs in 'Identity and Necessity') that 'Hesperus is Phosphorus' is necessarily true if true at all, but that isn't true of all examples. You might thus wonder, with respect to examples that don't work that way, what part 'a priori philosophical analysis' might play in our knowledge of their modal status. My account gives us an answer to this.
But another sort of question arose in the talk was how my account relates to two-dimensional semantics, and I was less satisfied with what I had to say on that. The true CI deciding proposition(s) in my account seem to play a role close to the role played by what world is actual in two-dimensional semantics. I worry that some in the audience were beginning to suspect that I've just laboriously re-arrived at two-dimensionalism along a somewhat different path. (And I'm getting a bit suspicious myself.)
So, I think that now, the most pressing task is to clarify the relationship of my new account to two-dimensional semantics, rather than to defend it further from counterexample. (This has always been a background concern, even with my old account, but now it has become urgent.) The notions in my account come up in a different way, and most formulations of two-dimensionalism seem to bring up difficulties which I may be able to avoid. My account seems more minimal and focused on its topic, and thus potentially more instructive.
Such anyway is my hunch, but it remains to make this clear.
In preparing the talk, I came to realise that I may have been too quick to assume that 'Air is airy' disproves my old account, according to which a proposition is necessarily true iff it is in the deductive closure of the set of propositions which are both true and inherently counterfactually invariant. Because 'There is nothing more to being air than being airy' is plausibly true and ICI, and it does - at least on a rich enough notion of impication - imply 'Air is airy'.
Now, if that's right, what follows? Are my new ideas about abandoning, in the analysis of necessity, the property of ICI for a relation of deciderhood, to be thrown out? I don't think so. Even if I was pushed towards them by the possibly wrong idea that my old account can't be defended from 'Air is airy', they still seem to give us an account which seems better. The old account now seems clumsy, so to speak. Maybe it can be understood in a way - with a rich notion of implication - so that it doesn't go wrong on 'Air is airy'. But this still seems like a kind of lucky break, and it's not clear to me that there aren't more threatening examples in the offing. The new account, on which a proposition is necessary iff it has a true positive counterfactual invariance decider, seems to reveal the notion's workings more faithfully, and seems less hostage to as-yet-unconsidered examples.
(Also note that, with the new account, you can use 'There's nothing more to being air than being airy' as your decider, but it seems like you can also use something like 'Air has no underlying nature' or 'Air is not a natural kind', and these do not seem to imply 'Air is airy' - they do not seem to contain that information. And since it seems you can plug these into the new account and conclude that 'Air is airy' is necessary, but cannot conclude the same on the same basis with the old account, that the new account is superior here, in enabling us to conclude necessity on a sometimes slenderer basis than we can using the old account.)
In the talk I gave, there were a number of questions and examples suggested which could look like they may disprove my account, but I was able to respond to all of them straightforwardly and to my account's credit. (With some elements of the new account, it's hard to see immediately why they're there and are as they are, but working through some examples clarifies things.) I also fielded a question (thanks to N.J.J. Smith) about how my account goes beyond what we already find in Kripke. There too I was able to give what I think is a satisfactory answer: the account isolates a plausibly a priori tractable, maybe broadly semantic, aspect to necessity. Kripke's work doesn't do this. He says a proposition is necessary if it holds in all the ways things could have been, and one of his main points is that we don't in general know a priori what these ways are. True, he also allows that we know by 'a priori philosophical analysis' (this occurs in 'Identity and Necessity') that 'Hesperus is Phosphorus' is necessarily true if true at all, but that isn't true of all examples. You might thus wonder, with respect to examples that don't work that way, what part 'a priori philosophical analysis' might play in our knowledge of their modal status. My account gives us an answer to this.
But another sort of question arose in the talk was how my account relates to two-dimensional semantics, and I was less satisfied with what I had to say on that. The true CI deciding proposition(s) in my account seem to play a role close to the role played by what world is actual in two-dimensional semantics. I worry that some in the audience were beginning to suspect that I've just laboriously re-arrived at two-dimensionalism along a somewhat different path. (And I'm getting a bit suspicious myself.)
So, I think that now, the most pressing task is to clarify the relationship of my new account to two-dimensional semantics, rather than to defend it further from counterexample. (This has always been a background concern, even with my old account, but now it has become urgent.) The notions in my account come up in a different way, and most formulations of two-dimensionalism seem to bring up difficulties which I may be able to avoid. My account seems more minimal and focused on its topic, and thus potentially more instructive.
Such anyway is my hunch, but it remains to make this clear.
Saturday, 6 May 2017
The Pre-Kripkean Puzzles are Back
Yes, but does Nature have no say at all here?! Yes.
It is just that she makes herself heard in a different way.
Wittgenstein (MS 137).
Modality was already puzzling before Kripke - there’s a tendency for the potted history of the thing to make it seem like just before Kripke, philosophers by and large thought they had a good understanding of modality. But there were deep problems and puzzles all along, and I think many were alive to them.
There is a funny thing about the effect of Kripke’s work which I have been starting to grasp lately. It seems like it jolted people out of certain dogmas, but that the problems with those dogmas were actually already there. The idea of the necessary a posteriori sort of stunned those ways of thinking. But once the dust settles and we learn to factor out the blatantly empirical aspect from subjunctive modality - two main ways have been worked out, more on which in a moment - the issue comes back, and those ways of thinking and the problems with them are just all still there.
(When I was working on my account of subjunctive necessity de dicto, I thought of most pre-Kripkan discussions of modality as irrelevant and boring. Now that I have worked that account out, they are seeming more relevant.)
What are the two ways of factoring out the aposterioricity of subjunctive modality? There is the two-dimensional way: construct “worlds” using the sort of language that doesn’t lead to necessary a posteriori propositions, and then make the truth-value of subjunctive modal claims involving the sort of language that does lead to them depend on which one of the worlds is actual.
This is currently the most prominent and best-known approach. However, it involves heady idealizations, many perplexing details, and various questionable assumptions. I think the difficulty of the two-dimensional approach has kept us in a kind of post-Kripkean limbo for a surprisingly long time now. Except perhaps in a few minds, it has not yet become very clear how the old pre-Kripkean problems are still lying in wait for us. I have hopes that the second way of factoring out will move things forward more powerfully (while I simultaneously hope for a clearer understanding of two-dimensionalism).
What is the second way? It is to observe that the subjunctively necessary propositions are those which are members of the deductive closure of the propositions which are both true and C, where C is some a priori tractable property. (On my account of C-hood, the closure version of the analysis is equivalent to the somewhat easier to understand claim that a proposition is necessary iff it is, or is implied by, a proposition which is both C and true. On Sider’s account of C-hood this equivalence fails.)
My account of subjunctive necessity explains condition C as inherent counterfactual invariance, which in turn is defined using the notion of a genuine counterfactual scenario description. And it is with these notions that the old-style puzzles come back up. Sider’s account has it that C-hood is just a conventional matter - something like an arbitrary, disjunctive list of kinds of propositions. (Here we get a revival of the old disagreements between conventionalists and those who were happy to explain modality semantically, but suspicious of conventionalism.)
What are these returning puzzles all about? They are about whether, and in what way, meaning and concepts are arbitrary. And about whether, and in what way, the world speaks through meaning and concepts. Hence the quote at the beginning, and the quote at the end of this companion post.
Saturday, 24 December 2016
What Are My Problems Now?
This is a follow-up to What Was My Problem?.
1. The Basis of Puzzlement about Modality
One line of investigation I would like to pursue now is into what might be called the basis of the puzzlement about modality. And as suggested by my experience of vaguely wrestling with a bunch of problems, before realizing that my strongest leading ideas for my thesis were really about some of these problems rather than others, I think this line of investigation may itself call for the distinguishing of various problems.
One locus of puzzlement about modality is the notion of metaphysical or subjunctive necessity as it applies to propositions. And one question about this notion is whether, and how, meaning comes into the picture. Also, just the question of how this notion relates to other notions, and the extent to which it can be analyzed (not necessarily in non-modal terms). Those problems are addressed, properly I hope, by the account in my thesis. But lots of what I was wrestling with at the beginning of my research remains, and does not attach specifically to the notion of subjunctive necessity de dicto; there is a lot that is puzzling about modality that my thesis does not address.
One puzzling thing which borders directly on my thesis work, and does have to do with the notion of subjunctive necessity de dicto, is the question of how this relates to de re modal constructions and quantification into modal contexts. But I have been very frustrated in my research here, and to be honest I have come to feel like it is a bit of a minor, abstruse issue compared to some of the more fundamental problems about modality (although I have no doubt that very interesting work could be done on that issue, and have a couple of ideas).
A more fundamental area I would like to work on is indicated by the question: Why is modality puzzling at all? But here too there are probably several puzzling things to distinguish. One thing I am not primarily thinking of, although it may end up becoming relevant to the problems I am grasping at, are questions about modality in an extremely general sense. For instance, the question of what unifies all uses of expressions which we call modal, or which we say are about possibility or whatever - including 'You can come in if you like', 'It could be that John is on his way', 'It is impossible for two colours to be in the same place', '"Hesperus is Phosphorus" is necessarily true', 'I can lift this weight', 'This apparatus has four possible configurations'. Also, questions about what generalizations can be made covering all or at least a great diversity of such uses, for instance about logical implication relations between them.
Rather, I am interested in trying to get at the basis of our puzzlement about what may be called objective modality. What does 'objective modality' mean? Well, one clear thing it does is exclude epistemic modals, like 'It could be that John is on his way' in natural uses. These are to be put to one side - at least initially - in the line of investigation I want to pursue. Likewise with uses of modal language having to do with permission. Within the puzzlement attaching primarily to objective modality as opposed to these set-aside kinds, important distinctions may have to be made. For instance, there may be a need to distinguish between more down-to-earth uses of modal language, for instance 'I can lift this weight', from what may be called more metaphysical uses - but not 'metaphysical' in the sense often used in modal philosophy, to mean either something like 'objective' or something a bit more specific, like picking out what I pick out with 'subjunctive'. Rather, by 'more metaphysical uses' I mean uses which are so to speak puzzling from the start. That is, where there isn't as much non-problematic, clearly useful use as in the case of 'I can lift this weight' and the like. E.g. 'The world could have been otherwise', 'Aristotle is essentially human'.
One way forward in this line of investigation would be to look critically and closely at philosophers' attempts to give a sense of the puzzlement about (objective) modality, often as a preliminary to some account or a survey of accounts. For instance, Sider's remarks on the subject in 'Reductive Theories of Modality'. But I think it will also be important to look within, so to speak, and keep seriously asking myself 'What is it that puzzles me about this?'.
2. Propositions and Meaning, Language Systems, and Our Expectations
Another line of investigation I would like to pursue has to do with the account of propositions and meaning sketched in chapter 6 of my thesis. That account appeals to a notion of an expression's internal meaning, cashed out in terms of the expression's role in the language system to which it belongs. This may raise questions about the nature of the system, and how we should think of it and describe it. In my thesis, I tried to remain quite open about this, emphasizing that I was offering a sketch, and that different fillings in of the detail here may be possible.
It was hard to avoid striking a false note here. For I do not think this is the whole story about my sketch, and the middle-Wittgenstein idea about role-in-system which it takes over; it may not be quite right to just think about it as a sketch of a theory, where some aspects are not filled in. For the very idea of what needs filling in, and how, should I think be scrutinized. It is not that I am advocating quietism, or defeatism, about questions about the 'language system' I appeal to. But I think that some of our expectations here may be in need of examination.
A curious thing happens in this territory - it is easy to become disoriented, and wonder what the problem was and what is needed now. Maybe sometimes in philosophy, as we solve problems, they slip from our grasp. Sometimes there is a strange feeling where we wonder something like: how could there be a solution here which is given in mere words? How could that ever do? We feel we still need to be taught something, or shown something. Could it be something practical, so to speak? I.e. something we could get through practice?
In the new year, I intend to use this blog to try to make some inroads into these and related problems.
1. The Basis of Puzzlement about Modality
One line of investigation I would like to pursue now is into what might be called the basis of the puzzlement about modality. And as suggested by my experience of vaguely wrestling with a bunch of problems, before realizing that my strongest leading ideas for my thesis were really about some of these problems rather than others, I think this line of investigation may itself call for the distinguishing of various problems.
One locus of puzzlement about modality is the notion of metaphysical or subjunctive necessity as it applies to propositions. And one question about this notion is whether, and how, meaning comes into the picture. Also, just the question of how this notion relates to other notions, and the extent to which it can be analyzed (not necessarily in non-modal terms). Those problems are addressed, properly I hope, by the account in my thesis. But lots of what I was wrestling with at the beginning of my research remains, and does not attach specifically to the notion of subjunctive necessity de dicto; there is a lot that is puzzling about modality that my thesis does not address.
One puzzling thing which borders directly on my thesis work, and does have to do with the notion of subjunctive necessity de dicto, is the question of how this relates to de re modal constructions and quantification into modal contexts. But I have been very frustrated in my research here, and to be honest I have come to feel like it is a bit of a minor, abstruse issue compared to some of the more fundamental problems about modality (although I have no doubt that very interesting work could be done on that issue, and have a couple of ideas).
A more fundamental area I would like to work on is indicated by the question: Why is modality puzzling at all? But here too there are probably several puzzling things to distinguish. One thing I am not primarily thinking of, although it may end up becoming relevant to the problems I am grasping at, are questions about modality in an extremely general sense. For instance, the question of what unifies all uses of expressions which we call modal, or which we say are about possibility or whatever - including 'You can come in if you like', 'It could be that John is on his way', 'It is impossible for two colours to be in the same place', '"Hesperus is Phosphorus" is necessarily true', 'I can lift this weight', 'This apparatus has four possible configurations'. Also, questions about what generalizations can be made covering all or at least a great diversity of such uses, for instance about logical implication relations between them.
Rather, I am interested in trying to get at the basis of our puzzlement about what may be called objective modality. What does 'objective modality' mean? Well, one clear thing it does is exclude epistemic modals, like 'It could be that John is on his way' in natural uses. These are to be put to one side - at least initially - in the line of investigation I want to pursue. Likewise with uses of modal language having to do with permission. Within the puzzlement attaching primarily to objective modality as opposed to these set-aside kinds, important distinctions may have to be made. For instance, there may be a need to distinguish between more down-to-earth uses of modal language, for instance 'I can lift this weight', from what may be called more metaphysical uses - but not 'metaphysical' in the sense often used in modal philosophy, to mean either something like 'objective' or something a bit more specific, like picking out what I pick out with 'subjunctive'. Rather, by 'more metaphysical uses' I mean uses which are so to speak puzzling from the start. That is, where there isn't as much non-problematic, clearly useful use as in the case of 'I can lift this weight' and the like. E.g. 'The world could have been otherwise', 'Aristotle is essentially human'.
One way forward in this line of investigation would be to look critically and closely at philosophers' attempts to give a sense of the puzzlement about (objective) modality, often as a preliminary to some account or a survey of accounts. For instance, Sider's remarks on the subject in 'Reductive Theories of Modality'. But I think it will also be important to look within, so to speak, and keep seriously asking myself 'What is it that puzzles me about this?'.
2. Propositions and Meaning, Language Systems, and Our Expectations
Another line of investigation I would like to pursue has to do with the account of propositions and meaning sketched in chapter 6 of my thesis. That account appeals to a notion of an expression's internal meaning, cashed out in terms of the expression's role in the language system to which it belongs. This may raise questions about the nature of the system, and how we should think of it and describe it. In my thesis, I tried to remain quite open about this, emphasizing that I was offering a sketch, and that different fillings in of the detail here may be possible.
It was hard to avoid striking a false note here. For I do not think this is the whole story about my sketch, and the middle-Wittgenstein idea about role-in-system which it takes over; it may not be quite right to just think about it as a sketch of a theory, where some aspects are not filled in. For the very idea of what needs filling in, and how, should I think be scrutinized. It is not that I am advocating quietism, or defeatism, about questions about the 'language system' I appeal to. But I think that some of our expectations here may be in need of examination.
A curious thing happens in this territory - it is easy to become disoriented, and wonder what the problem was and what is needed now. Maybe sometimes in philosophy, as we solve problems, they slip from our grasp. Sometimes there is a strange feeling where we wonder something like: how could there be a solution here which is given in mere words? How could that ever do? We feel we still need to be taught something, or shown something. Could it be something practical, so to speak? I.e. something we could get through practice?
In the new year, I intend to use this blog to try to make some inroads into these and related problems.
Wednesday, 9 March 2016
Five Objections to Sider's Quasi-Conventionalism About Modality
There are a couple of infelicities in the below which have been fixed in the version of this material appearing in chapter 4 of my PhD thesis Necessity and Propositions.
In a recent post I described Sider's quasi-conventionalism about modality, which in my view takes an important step forward with respsect to necessity de dicto but is mistaken in other ways. (My account of necessity de dicto shares a structure with it.) Here I give five objections to Sider's view.
In a recent post I described Sider's quasi-conventionalism about modality, which in my view takes an important step forward with respsect to necessity de dicto but is mistaken in other ways. (My account of necessity de dicto shares a structure with it.) Here I give five objections to Sider's view.
None of these take the form of counterexamples. As Merricks (2013) observes:
[...] Sider’s general approach—as opposed to specific instances of that approach—is immune to counterexample. For suppose that Sider lists the “certain sorts.” You then come up with an absolutely compelling example of a proposition that is necessarily true and not of a sort on the list. Sider need not abandon his overall approach to reducing necessity. Instead, he could just add a new sort to the list to accommodate that example. Or suppose you come up with an absolutely compelling example of a true proposition that is not necessarily true and is of a sort on the list. Sider could just expunge that sort from the list.
1. Necessity does not seem disjunctive or arbitrary (at least, not to this extent).
This is an objection centering on our intuitive grasp of the concept of necessity de dicto. It seems like this is a notion we can grasp, with the help of Kripke’s characterizations as supplemented in this post. Now, when we grasp this idea, it seems we are grasping a single, unified concept: necessary truths could not have been otherwise, no matter how things had turned out. This just doesn’t seem like a disjunctive matter, and nor does it seem like the sort of thing we make one way or the other with any kind of arbitration - although of course there are unclear or borderline cases, which we may perhaps make stipulations about to some extent.
This is not a knock-down objection, of course. Sometimes philosophy can reveal things to be other than they might seem. But I think it is hard to deny, if we are willing and able to grasp the concept of necessity de dicto and careful to hold in abeyance any of our pet theoretical proclivities which may suggest otherwise, that the notion does seem more unitary and less arbitrary than Sider’s theory would have us believe. And I propose that that should count as a mark against Sider’s theory.
Furthermore, insofar as appearance really is different from what Sider says the reality is when it comes to necessity, there is some explanatory work for Sider, or more generally the would-be quasi-conventionalist, to do here: why the discrepancy? As far as I know, no answer has yet been given.
2. The ersatz substitute worry.
A starting point for this worry is the unapologetically ad hoc nature of Sider’s successive extensions of the toy version of his approach that he begins with (where the “certain sort” of propositions he takes as “modal axioms” are just the mathematical truths). This process seems to be one of going back and forth between a growing list of types of propositions, the list at the heart of an increasingly disjunctive account, and our grasp of the real modal notion of necessity. This gives rise to the worry that all we are doing is building an ersatz substitute for the real notion, by looking at the extensional behaviour of the latter and stipulating this behaviour into the account. No matter how far we pursue this strategy, the disjunctive notion we are building will remain fundamentally different in character from the notion whose behaviour we are modelling with it. Supposing that what we want from an ‘if and only if’ style account of necessity de dicto is not some substitute for that notion, but a biconditional which gives us insight into the notion itself, Sider’s approach will never satisfy.
Something of this worry is even suggested by what Sider says about family resemblances, rehearsed in the previous post as point (6). The quasi-conventionalist could simply insist that each of the items on their list of the types of propositions which count as modal axioms is there as a brute fact - that’s just how the notion of necessity works. But, Sider says, the quasi-conventionalist ‘need not be quite so flat-footed’, and is ‘free to exhibit similarities between various modal axioms, just as one might exhibit similarities between things that fall under our concept of a game, to use Wittgenstein’s example’. This move, offered as an optional extra for the quasi-conventionalist, is plausibly in tension with the way Sider’s successively extended accounts are formulated. Just as the concept of a game - allowing for the sake of argument that it is a family resemblance concept - is plausibly not actually captured by any particular disjunction, but is as we might say inherently open-ended, it is also plausible that we should admit that the real “certain sort” or “modal axiom” notion doing the all-important work in Sider’s account - allowing for the sake of argument that it is a family resemblance concept - is not captured by any particular disjunction either.
This of course suggests a variant of Sider’s approach, where it is held that the “modal axiom” notion is a family resemblance concept, and admitted that any definite, disjunctive list of types of propositions could only yield, when plugged into the overall account, an ersatz substitute for the notion of necessity de dicto. This variant is not, or at any rate less, vulnerable to the the ersatz substitute worry. But it is not clear whether it could really satisfy a philosopher who wants insight into the notion of necessity de dicto, let alone a philosopher with Sider’s motivations. For instance, can it really claim to be modally reductive? It might on the contrary seem that the family resemblance notion in question should be counted as thoroughly modal. Furthermore, it may seem to yield an account which is insufficiently insightful - essentially all we are now getting is (Schema) itself, together with the pronouncement that the condition C is given by a family resemblance concept. Is there nothing more which can be said? Relatedly, the question now arises: is it after all true that the notion in question is a family resemblance concept? What reason have we to believe that? (I will suggest, somewhat ironically given that I am on the whole much more admiring of Wittgenstein’s philosophy than Sider is, that it isn’t true. The notion playing this ‘condition C’ role, i.e. the notion which when combined with the notion of truth yields a notion playing Sider’s “modal axiom” role, can be defined in terms of a single necessary and sufficient condition.)
3. No iteration?
When Sider says early on in the modality chapter of his (2011) that the account he offers will be partial, there is a footnote to this remark which runs as follows:
This raises the question: how come, faced with this failure of coverage, Sider doesn’t simply make the same move with modal statements as he does with analyticities, “metaphysical” statements, and natural kind statements - namely include them expressly in the account?This is an objection centering on our intuitive grasp of the concept of necessity de dicto. It seems like this is a notion we can grasp, with the help of Kripke’s characterizations as supplemented in this post. Now, when we grasp this idea, it seems we are grasping a single, unified concept: necessary truths could not have been otherwise, no matter how things had turned out. This just doesn’t seem like a disjunctive matter, and nor does it seem like the sort of thing we make one way or the other with any kind of arbitration - although of course there are unclear or borderline cases, which we may perhaps make stipulations about to some extent.
This is not a knock-down objection, of course. Sometimes philosophy can reveal things to be other than they might seem. But I think it is hard to deny, if we are willing and able to grasp the concept of necessity de dicto and careful to hold in abeyance any of our pet theoretical proclivities which may suggest otherwise, that the notion does seem more unitary and less arbitrary than Sider’s theory would have us believe. And I propose that that should count as a mark against Sider’s theory.
Furthermore, insofar as appearance really is different from what Sider says the reality is when it comes to necessity, there is some explanatory work for Sider, or more generally the would-be quasi-conventionalist, to do here: why the discrepancy? As far as I know, no answer has yet been given.
2. The ersatz substitute worry.
A starting point for this worry is the unapologetically ad hoc nature of Sider’s successive extensions of the toy version of his approach that he begins with (where the “certain sort” of propositions he takes as “modal axioms” are just the mathematical truths). This process seems to be one of going back and forth between a growing list of types of propositions, the list at the heart of an increasingly disjunctive account, and our grasp of the real modal notion of necessity. This gives rise to the worry that all we are doing is building an ersatz substitute for the real notion, by looking at the extensional behaviour of the latter and stipulating this behaviour into the account. No matter how far we pursue this strategy, the disjunctive notion we are building will remain fundamentally different in character from the notion whose behaviour we are modelling with it. Supposing that what we want from an ‘if and only if’ style account of necessity de dicto is not some substitute for that notion, but a biconditional which gives us insight into the notion itself, Sider’s approach will never satisfy.
Something of this worry is even suggested by what Sider says about family resemblances, rehearsed in the previous post as point (6). The quasi-conventionalist could simply insist that each of the items on their list of the types of propositions which count as modal axioms is there as a brute fact - that’s just how the notion of necessity works. But, Sider says, the quasi-conventionalist ‘need not be quite so flat-footed’, and is ‘free to exhibit similarities between various modal axioms, just as one might exhibit similarities between things that fall under our concept of a game, to use Wittgenstein’s example’. This move, offered as an optional extra for the quasi-conventionalist, is plausibly in tension with the way Sider’s successively extended accounts are formulated. Just as the concept of a game - allowing for the sake of argument that it is a family resemblance concept - is plausibly not actually captured by any particular disjunction, but is as we might say inherently open-ended, it is also plausible that we should admit that the real “certain sort” or “modal axiom” notion doing the all-important work in Sider’s account - allowing for the sake of argument that it is a family resemblance concept - is not captured by any particular disjunction either.
This of course suggests a variant of Sider’s approach, where it is held that the “modal axiom” notion is a family resemblance concept, and admitted that any definite, disjunctive list of types of propositions could only yield, when plugged into the overall account, an ersatz substitute for the notion of necessity de dicto. This variant is not, or at any rate less, vulnerable to the the ersatz substitute worry. But it is not clear whether it could really satisfy a philosopher who wants insight into the notion of necessity de dicto, let alone a philosopher with Sider’s motivations. For instance, can it really claim to be modally reductive? It might on the contrary seem that the family resemblance notion in question should be counted as thoroughly modal. Furthermore, it may seem to yield an account which is insufficiently insightful - essentially all we are now getting is (Schema) itself, together with the pronouncement that the condition C is given by a family resemblance concept. Is there nothing more which can be said? Relatedly, the question now arises: is it after all true that the notion in question is a family resemblance concept? What reason have we to believe that? (I will suggest, somewhat ironically given that I am on the whole much more admiring of Wittgenstein’s philosophy than Sider is, that it isn’t true. The notion playing this ‘condition C’ role, i.e. the notion which when combined with the notion of truth yields a notion playing Sider’s “modal axiom” role, can be defined in terms of a single necessary and sufficient condition.)
3. No iteration?
When Sider says early on in the modality chapter of his (2011) that the account he offers will be partial, there is a footnote to this remark which runs as follows:
(16) For example, the account defines a property of propositions that do not themselves concern modality, and thus is insufficient to interpret iterable modal operators.
Perhaps the answer is that this would threaten the account’s claim of reductiveness. For it seems that in order to include modal statements on the list, we need the concept ‘modal’.
The question then becomes: is ‘modal’ modal? If it is, Sider’s account is in serious trouble: it cannot, as a matter of principle, handle iterated modality. For remember, it is supposed to be modally reductive. And if iterated modality is a real, legitimate thing, then what use is a theory which gives us - by design - some extensionally correct answers but cannot handle this whole class of cases? It seems such a theory could give us an ersatz substitute for modality at best (to recall the above objection by that name). Its failure, if it is a failure, to be extendable to a salient class of cases should perhaps suggest to us that it is on the wrong track.
So, is ‘modal’ modal? It is an interesting question, and suggests interesting analogous questions about other kinds of concepts. One reason to think it is, is that we don’t seem to have a general way of saying what ‘modal’ means which doesn’t work by way of example. We seem to need examples of modal notions - necessity, or contingency, or possibility, or impossibility, or some combination of them - to do the job. To be sure, we could be said to be mentioning rather than using these notions in our explanations of ‘modal’, but is that any help? Don’t we need to use them in some broad sense in order to mention them in the appropriate way?
Another way out which may occur to the reader is to somehow delineate the modal statements using notions which are distinct from ‘modal’ and the like, but which fortuitously give the right extension. I am pessimistic about this. For a start, I can’t think of any good candidate notions. Furthermore, even if there were notions around which could do the job, wouldn’t using them for this purpose play further into the ersatz substitute worry described above? In particular, it seems like this strategy, while it may help Sider’s account deliver extensionally correct answers, would take the account (even) further from the real meaning of modal expressions, or the real nature of modal notions.
One possible strategy remains to be considered: accepting that ‘modal’ is modal and simply giving up the claim to full modal reductivity. From one angle, this seems not unreasonable; the way that ‘modal’ introduces modality, assuming it does, into the account, seems quite special and different from the way modality would be introduced if a notion of possibility or necessity were directly used. So perhaps there is room to claim that a broadly Siderian quasi-conventionalist account involving the notion of ‘modal’ as an unreduced modal element could still constitute a theoretical advance. I have no knockdown objection to this, but I do want to suggest that once this concession is made, other objections, such as the first two considered here - (i) that necessity does not seem as disjunctive or arbitrary as quasi-conventionalism would have us believe and (ii) the ersatz substitute worry - become all the more acute; I am not sympathetic with the following sort of move, but you might try to argue that biting those bullets is worth it if we get in return a complete reduction of modality, with its attendant payoff in eliminating puzzlement and vindicating certain sorts of metaphysical visions, but you can’t do that anymore under the present strategy. Indeed, the whole spirit of the quasi-conventionalist approach seems to be in tension with allowing such a modal element into the mix.
In sum, there is reason to suspect that iterated modality, and the failure of any existing version of Sider’s approach to cover it, poses a serious threat to Sider’s approach in general.
4. Reductivity a bug, not a feature.
Essentially this objection is raised against Sider’s theory by Merricks (2013). The objection is simply that, if we have reason to think that a modal notion like that of necessity de dicto cannot be reduced to non-modal notions, or if we just intuitively feel that to be right, then we should on that score alone be suspicious of Sider’s theory, since it purports to give a reduction. In making this objection, Merricks cites an argument he gives elsewhere (namely in Chapter 5 of his (2007)) for the conclusion that such modal notions indeed cannot be reduced to non-modal ones.
5. Questionable motivation.
As we said at the outset, Sider’s account is partly motivated by general puzzlement about modality, and partly by a metaphysical vision. Both these facets of the motivation can be made the focus of criticism. The following is not supposed to constitute a sharp, incisive objection, but rather to cast some doubt on these general features of Sider’s approach.
Regarding general puzzlement: yes, modality is puzzling to philosophers. But perhaps this puzzlement is not to be treated exclusively by means of reduction (or, for that matter, by ‘if and only if’ analysis whether modally reductive or not). Indeed, pursuing reduction can even be seen as pursuing an easy way out - albeit one which may be impossible in principle. Perhaps the only real way forward, with parts of our puzzlement at least, is, rather than trying to reduce modality to non-modal terms, to work on our way of looking at modal concepts themselves, using philosophical methods other than reductive analysis. (One method which comes to mind is the method, due to Wittgenstein, of imagining simplified language games and comparing and contrasting them to ours. In the Brown Book some steps are taken towards doing this with modality, but only cursorily. I mention this to give a particularly concrete and well-known example of a possibly helpful method, but this is just one among many - I do not mean to suggest it could suffice all by itself.) Non-modally-reductive accounts of necessity de dicto such as mine do not face this criticism, since they do not aim to clear up all of our puzzlement about modality, or even just some core of it, by means of an ‘if and only if’ style analysis. Nor do they aim even to point the way to such a clearing up. By being less ambitious on that front, they offer a more realistic hope of genuine theoretical progress on our understanding of de dicto modal notions - how they relate to other notions both modal and non-modal.
Regarding the metaphysical vision: it is beyond the scope of this post to criticize Sider’s Hume-influenced, Lewis-influenced metaphysical vision head-on. But we may note that, insofar as there may be grave problems with this sort of metaphysics for all we know given the present state of philosophical inquiry - nothing of the sort may be tenable, ultimately - there may also be problems with a highly ambitious approach to modality which is in service of this sort of metaphysics. More generally, perhaps there is reason to be dubious of any approach to modality based upon a metaphysical vision. One reason may be that the vision is, so to speak, too antecedent to modal considerations: perhaps one should let modal considerations shape one’s approach to metaphysical questions, rather than trying to explain modality (away, if you like) in terms of an approach to metaphysical questions which had its appeal quite apart from, or even in spite of, modal considerations. Another reason may be that the best way to make theoretical progress on the notion of necessity de dicto is to keep sweeping metaphysical visions out of it. We may do better to instead treat our topic along broadly logical lines. One way this may help is that it might free us up to throw a wider variety of conceptual resources at the problem - for instance, semantic notions or other modal notions which may seem problematic against some special metaphysical backdrop but are actually quite in order.
That concludes our list of objections or worries. For two further objections, see Merricks (2013).
I think the cumulative effect of the objections canvassed above should be for us to regard Sider’s theory as highly problematic. But note that none of these objections threaten (Schema). This raises the question: what if these were a more soberly motivated, more theoretically satisfying (Schema)-embodying account available? Some other candidate for the condition C in (Schema) which avoids these objections?
References
Merricks, Trenton (2007). Truth and Ontology. Oxford University Press.
Merricks, Trenton (2013). Three Comments on Writing the Book of the World. Analysis 73 (4):722-736.
Sider, Theodore (2003). Reductive theories of modality. In Michael J. Loux & Dean W. Zimmerman (eds.), The Oxford Handbook of Metaphysics. Oxford University Press 180-208.
Sider, Theodore (2011). Writing the Book of the World. Oxford University Press.
Sider, Theodore (2013). Symposium on Writing the Book of the World. Analysis 73 (4):751-770.
So, is ‘modal’ modal? It is an interesting question, and suggests interesting analogous questions about other kinds of concepts. One reason to think it is, is that we don’t seem to have a general way of saying what ‘modal’ means which doesn’t work by way of example. We seem to need examples of modal notions - necessity, or contingency, or possibility, or impossibility, or some combination of them - to do the job. To be sure, we could be said to be mentioning rather than using these notions in our explanations of ‘modal’, but is that any help? Don’t we need to use them in some broad sense in order to mention them in the appropriate way?
Another way out which may occur to the reader is to somehow delineate the modal statements using notions which are distinct from ‘modal’ and the like, but which fortuitously give the right extension. I am pessimistic about this. For a start, I can’t think of any good candidate notions. Furthermore, even if there were notions around which could do the job, wouldn’t using them for this purpose play further into the ersatz substitute worry described above? In particular, it seems like this strategy, while it may help Sider’s account deliver extensionally correct answers, would take the account (even) further from the real meaning of modal expressions, or the real nature of modal notions.
One possible strategy remains to be considered: accepting that ‘modal’ is modal and simply giving up the claim to full modal reductivity. From one angle, this seems not unreasonable; the way that ‘modal’ introduces modality, assuming it does, into the account, seems quite special and different from the way modality would be introduced if a notion of possibility or necessity were directly used. So perhaps there is room to claim that a broadly Siderian quasi-conventionalist account involving the notion of ‘modal’ as an unreduced modal element could still constitute a theoretical advance. I have no knockdown objection to this, but I do want to suggest that once this concession is made, other objections, such as the first two considered here - (i) that necessity does not seem as disjunctive or arbitrary as quasi-conventionalism would have us believe and (ii) the ersatz substitute worry - become all the more acute; I am not sympathetic with the following sort of move, but you might try to argue that biting those bullets is worth it if we get in return a complete reduction of modality, with its attendant payoff in eliminating puzzlement and vindicating certain sorts of metaphysical visions, but you can’t do that anymore under the present strategy. Indeed, the whole spirit of the quasi-conventionalist approach seems to be in tension with allowing such a modal element into the mix.
In sum, there is reason to suspect that iterated modality, and the failure of any existing version of Sider’s approach to cover it, poses a serious threat to Sider’s approach in general.
4. Reductivity a bug, not a feature.
Essentially this objection is raised against Sider’s theory by Merricks (2013). The objection is simply that, if we have reason to think that a modal notion like that of necessity de dicto cannot be reduced to non-modal notions, or if we just intuitively feel that to be right, then we should on that score alone be suspicious of Sider’s theory, since it purports to give a reduction. In making this objection, Merricks cites an argument he gives elsewhere (namely in Chapter 5 of his (2007)) for the conclusion that such modal notions indeed cannot be reduced to non-modal ones.
5. Questionable motivation.
As we said at the outset, Sider’s account is partly motivated by general puzzlement about modality, and partly by a metaphysical vision. Both these facets of the motivation can be made the focus of criticism. The following is not supposed to constitute a sharp, incisive objection, but rather to cast some doubt on these general features of Sider’s approach.
Regarding general puzzlement: yes, modality is puzzling to philosophers. But perhaps this puzzlement is not to be treated exclusively by means of reduction (or, for that matter, by ‘if and only if’ analysis whether modally reductive or not). Indeed, pursuing reduction can even be seen as pursuing an easy way out - albeit one which may be impossible in principle. Perhaps the only real way forward, with parts of our puzzlement at least, is, rather than trying to reduce modality to non-modal terms, to work on our way of looking at modal concepts themselves, using philosophical methods other than reductive analysis. (One method which comes to mind is the method, due to Wittgenstein, of imagining simplified language games and comparing and contrasting them to ours. In the Brown Book some steps are taken towards doing this with modality, but only cursorily. I mention this to give a particularly concrete and well-known example of a possibly helpful method, but this is just one among many - I do not mean to suggest it could suffice all by itself.) Non-modally-reductive accounts of necessity de dicto such as mine do not face this criticism, since they do not aim to clear up all of our puzzlement about modality, or even just some core of it, by means of an ‘if and only if’ style analysis. Nor do they aim even to point the way to such a clearing up. By being less ambitious on that front, they offer a more realistic hope of genuine theoretical progress on our understanding of de dicto modal notions - how they relate to other notions both modal and non-modal.
Regarding the metaphysical vision: it is beyond the scope of this post to criticize Sider’s Hume-influenced, Lewis-influenced metaphysical vision head-on. But we may note that, insofar as there may be grave problems with this sort of metaphysics for all we know given the present state of philosophical inquiry - nothing of the sort may be tenable, ultimately - there may also be problems with a highly ambitious approach to modality which is in service of this sort of metaphysics. More generally, perhaps there is reason to be dubious of any approach to modality based upon a metaphysical vision. One reason may be that the vision is, so to speak, too antecedent to modal considerations: perhaps one should let modal considerations shape one’s approach to metaphysical questions, rather than trying to explain modality (away, if you like) in terms of an approach to metaphysical questions which had its appeal quite apart from, or even in spite of, modal considerations. Another reason may be that the best way to make theoretical progress on the notion of necessity de dicto is to keep sweeping metaphysical visions out of it. We may do better to instead treat our topic along broadly logical lines. One way this may help is that it might free us up to throw a wider variety of conceptual resources at the problem - for instance, semantic notions or other modal notions which may seem problematic against some special metaphysical backdrop but are actually quite in order.
That concludes our list of objections or worries. For two further objections, see Merricks (2013).
I think the cumulative effect of the objections canvassed above should be for us to regard Sider’s theory as highly problematic. But note that none of these objections threaten (Schema). This raises the question: what if these were a more soberly motivated, more theoretically satisfying (Schema)-embodying account available? Some other candidate for the condition C in (Schema) which avoids these objections?
References
Merricks, Trenton (2007). Truth and Ontology. Oxford University Press.
Merricks, Trenton (2013). Three Comments on Writing the Book of the World. Analysis 73 (4):722-736.
Sider, Theodore (2003). Reductive theories of modality. In Michael J. Loux & Dean W. Zimmerman (eds.), The Oxford Handbook of Metaphysics. Oxford University Press 180-208.
Sider, Theodore (2011). Writing the Book of the World. Oxford University Press.
Sider, Theodore (2013). Symposium on Writing the Book of the World. Analysis 73 (4):751-770.
Saturday, 13 February 2016
Sider's Quasi-Conventionalism About Modality
Starting in his (2003), and in an unpublished draft from around the same time which is not to be cited, Theodore Sider has proposed a theory of necessity de dicto called quasi-conventionalism. The most up to date version can be found in his (2011) and his replies to a symposium on that work. It states necessary and sufficient conditions for a proposition to be necessary, but as we will see, one of the key concepts involved has been left open-ended, so the account is to be regarded as partial. The account is supposed to reduce necessity de dicto to non-modal notions, and to be extendable to de re modality.
What makes Sider’s account so worthy of discussion from my point of view is that it takes what I believe to be an important step forward with respect to the task of giving an account of necessity de dicto. The step forward is that it embodies a certain structure, which my account shares. Abstracting from the details of Sider’s account, the shared structure can be expressed in the form of a schematic analysis as follows:
(Schema) A proposition is necessary iff it is, or is implied by, a proposition which is both true and meets a certain condition C.
(Sider, as we shall see, does not quite use his schema, but his analysis can easily be re-expressed so as to conform to it.)
So, Sider’s view takes, as I will argue, an important step forward. But it also has grave defects. Considering Sider’s view, then - seeing that it instantiates the suggestive and appealing (Schema), and seeing what is wrong with it - offers a nice way of leading up to and motivating my own account, which I will give in the next chapter. (This is not the way I actually arrived at my account, but it could have been.)
Two of SIder’s main starting points seem to be: (i) the desire to find a way of reducing modal concepts to non-modal concepts, and (ii) a hunch that conventionalist theories according to which necessities are true by convention were on to something: roughly, that convention should play some key role in the analysis of necessity. Regarding (i) and the underlying motivation for it, there are two interrelated strands here: one is a relatively theory-neutral feeling that modality is mysterious, or cries out for explanation, but this then plays into the second strand, which is emphasized in his (2011): a desire for an account of the “fundamental nature of reality”, “reality’s fundamental structure” - an account that “carves nature at the joints”.
Sider argues that it was always a mistake to try to account for necessary truth by means of the idea of truth by convention: the idea is of dubious coherence, and in view of necessary a posteriori truths especially, would not seem to line up with the idea of necessary truth anyway. But that doesn’t mean convention can’t play a crucial role in, not truth-making, but necessity-making, or accounting for the necessity of necessary truths. (I make the analogous point, with the meanings or natures of propositions in place of convention, in arguing for my account.) Part of the motivation and attraction of truth by convention theories of necessity, Sider allows, was their promise of shedding light on the epistemology of logic and mathematics. The theory of modality Sider is offering makes no claim to do that. But so what? Who says the place to look for insight into the epistemology of logic and mathematics is in a theory of modality?
In his (2011), Sider labels his account ‘Humean’. Here is his first pass at expressing it there:
What makes Sider’s account so worthy of discussion from my point of view is that it takes what I believe to be an important step forward with respect to the task of giving an account of necessity de dicto. The step forward is that it embodies a certain structure, which my account shares. Abstracting from the details of Sider’s account, the shared structure can be expressed in the form of a schematic analysis as follows:
(Schema) A proposition is necessary iff it is, or is implied by, a proposition which is both true and meets a certain condition C.
(Sider, as we shall see, does not quite use his schema, but his analysis can easily be re-expressed so as to conform to it.)
So, Sider’s view takes, as I will argue, an important step forward. But it also has grave defects. Considering Sider’s view, then - seeing that it instantiates the suggestive and appealing (Schema), and seeing what is wrong with it - offers a nice way of leading up to and motivating my own account, which I will give in the next chapter. (This is not the way I actually arrived at my account, but it could have been.)
Two of SIder’s main starting points seem to be: (i) the desire to find a way of reducing modal concepts to non-modal concepts, and (ii) a hunch that conventionalist theories according to which necessities are true by convention were on to something: roughly, that convention should play some key role in the analysis of necessity. Regarding (i) and the underlying motivation for it, there are two interrelated strands here: one is a relatively theory-neutral feeling that modality is mysterious, or cries out for explanation, but this then plays into the second strand, which is emphasized in his (2011): a desire for an account of the “fundamental nature of reality”, “reality’s fundamental structure” - an account that “carves nature at the joints”.
Sider argues that it was always a mistake to try to account for necessary truth by means of the idea of truth by convention: the idea is of dubious coherence, and in view of necessary a posteriori truths especially, would not seem to line up with the idea of necessary truth anyway. But that doesn’t mean convention can’t play a crucial role in, not truth-making, but necessity-making, or accounting for the necessity of necessary truths. (I make the analogous point, with the meanings or natures of propositions in place of convention, in arguing for my account.) Part of the motivation and attraction of truth by convention theories of necessity, Sider allows, was their promise of shedding light on the epistemology of logic and mathematics. The theory of modality Sider is offering makes no claim to do that. But so what? Who says the place to look for insight into the epistemology of logic and mathematics is in a theory of modality?
In his (2011), Sider labels his account ‘Humean’. Here is his first pass at expressing it there:
To say that a proposition is necessary, according to the Humean, is to say that the proposition is i) true; and ii) of a certain sort. A crude Humean view, for example, would say that a proposition is necessary iff it is either a logical or mathematical truth. What determines the “certain sort” of propositions? Nothing “metaphysically deep”. For the Humean, necessity does not carve at the joints. There are many candidate meanings for ‘necessary’, corresponding to different “certain sorts” our linguistic community might choose. (Sider 2011, p. 269.)
The role of convention in Sider’s account, then, lies in distinguishing this “certain sort” - or “certain sorts” (Sider switches as this point to the plural):
Perhaps the choice of the “certain sorts” is conventional. Convention can do this without purporting to make true the statements of logic or mathematics (or, for that matter, statements to the effect that these truths are necessary), for the choice of the certain sorts is just a choice about what to mean by ‘necessary’. Or perhaps the choice is partly subjective/projective rather than purely conventional. (p. 270.)
As can be seen at the end of this last quote, Sider has some uncertainty about whether the choice of the “certain sorts” is ‘purely conventional’. We will not get deeply into Sider’s ideas of ‘conventional’ and ‘subjective/projective’ here. It is enough for our purposes that the “certain sorts” are, for Sider, ‘not objectively distinguished’ (p. 270). Or again in different words:
The core idea of the Humean account, then, is that necessary truths are truths of certain more or less arbitrarily selected kinds. (p. 271.)
At this point Sider introduces a refinement, and it is this that will allow us to see how Sider’s account embodies (Schema) above:
More carefully: begin with a set of modal axioms and a set of modal rules. Modal axioms are simply certain chosen true sentences; modal rules are certain chosen truth-preserving relations between sets of sentences and sentences. To any chosen modal axioms and rules there corresponds a set of modal theorems: the closure of the set of modal axioms under the rules.[footnote omitted] Any choice of modal axioms and modal rules, and thus of modal theorems, results in a version of Humeanism: to be necessary is to be a modal theorem thus understood.[footnote omitted] (“Modal” axioms, rules, and theorems are so-called because of their role in the Humean theory of modality, but the goal is to characterize them nonmodally; otherwise the theory would fail to be reductive. [...]) (p. 271.)
Then, getting more specific with a preliminary proposal:
A simple version of Humeanism to begin with: the sole modal rule is first‐order logical consequence, and the modal axioms are the mathematical truths. (Logical truths are logical consequences of any propositions whatsoever, and so do not need to be included as modal axioms.) (pp. 271 - 272.)
At this point, we can see how Sider’s account, or type of account, will embody (Schema); his notion of ‘modal axiom’ combines the requirements of truth and being of a “certain sort” (or one of “certain sorts”), and the main point of the ‘modal rules’ seems clearly to be to draw out implications of the axioms. So, separating the truth and “certain sort” requirements again, we can with little or no distortion put Sider’s preferred type of account into (Schema):
(SiderSchema) A proposition is necessary iff it is, or is implied by, a proposition which is both true and is of a more or less arbitrarily selected “certain sort”.
The presence in the account of implication (or something like it) is in my view an important and laudable feature. It is perhaps not sufficiently emphasized by Sider, and has been glossed over in subsequent discussion of his view. For instance, Merricks (2013) glosses Sider’s account as saying that ‘Sider reduces a proposition p’s being necessarily true to: p is true-and-mathematical or true-and-logical or true-and-metaphysical or…’. The importance of implication (or something like it) in (Schema) and views embodying it is made clear in my recent post on my account.
After giving his preliminary version of Humeanism, Sider goes on to consider a series of worries, responding with ‘a combination of refinement and argument’ (p. 272.) He never arrives at a definitive proposal, but aims to develop his strategy sufficiently to justify his general approach.
I think we have already gotten a pretty good sense of Sider’s approach, but I want more or less to complete the exposition of Sider’s approach before, in my next post, moving on to objections, none of which are among the worries Sider considers. So before moving on to objections, I will now briefly convey six further points which emerge in Sider’s responses to the worries.
(SiderSchema) A proposition is necessary iff it is, or is implied by, a proposition which is both true and is of a more or less arbitrarily selected “certain sort”.
The presence in the account of implication (or something like it) is in my view an important and laudable feature. It is perhaps not sufficiently emphasized by Sider, and has been glossed over in subsequent discussion of his view. For instance, Merricks (2013) glosses Sider’s account as saying that ‘Sider reduces a proposition p’s being necessarily true to: p is true-and-mathematical or true-and-logical or true-and-metaphysical or…’. The importance of implication (or something like it) in (Schema) and views embodying it is made clear in my recent post on my account.
After giving his preliminary version of Humeanism, Sider goes on to consider a series of worries, responding with ‘a combination of refinement and argument’ (p. 272.) He never arrives at a definitive proposal, but aims to develop his strategy sufficiently to justify his general approach.
I think we have already gotten a pretty good sense of Sider’s approach, but I want more or less to complete the exposition of Sider’s approach before, in my next post, moving on to objections, none of which are among the worries Sider considers. So before moving on to objections, I will now briefly convey six further points which emerge in Sider’s responses to the worries.
- Logical consequence must be non-modal: Sider wants his account to avoid modal notions, so modal characterizations of logical consequence are out. Remaining options include primitivism about logical consequence, something Sider calls the “best system” account of logical truth (which he describes in section 10.3 of his (2011)) extended to an account of logical consequence, and model theoretic approaches.
- Analytic truths added as axioms: Sider holds that analytic truths should come out necessary, and proposes to that end that each analytic truth be added as a modal axiom (p. 274). This move is unapologetically ad hoc. (You might worry, as I do, that some examples of the contingent a priori should count as analytic, in which case not all analyticities are necessities. But perhaps there are different notions of analyticity which may give different results here. In any case let’s set this aside.)
- “Metaphysical” statements added as axioms: again, modulo some fuzziness about what it takes for a statement to count as metaphysical - the gloss Sider uses is ‘truths about fundamental and abstract matters’ (p. 275) - true metaphysical statements are to be added as axioms. Again this is unapologetically ad hoc, or treated as a brute fact: ‘What justifies their status as modal axioms? This is just how the concept of necessity works. Such propositions have no further feature that explains their inclusion as modal axioms.’ (p. 275)
- A new class of ‘natural kind axioms’: another unapologetically ad hoc addition, this time to accommodate the necessity of natural kind type examples of the necessary a posteriori, e.g. ‘Water is H20’. I refer the reader to (pp. 282 - 283) for details.
- Contextual variation of the “outer modality”: it is conventional wisdom that modal talk in the wild should be understood as being about a contextually variable space of possibilities. This is often combined with a picture of an outer, unrestricted space of possibilities which does not vary. Sider suggests, as ‘more attractive’ (p. 281), that even the outer space is contextually variable - that ‘there can be contextual variation both in the modal axioms and the modal rules’ (p. 281).
- Family resemblances (maybe): on (p. 288) Sider rehearses his (by now familiar) attitude to necessity thus: ‘Why are logical (or mathematical, or analytic, or …) truths necessary? The Humean’s answer is that this is just how our concept of necessity works.’ But then he turns around and suggests (pp. 288-289) that ‘a Humean need not be quite so flatfooted. [...] [The Humean] resists the idea that there is a single necessary and sufficient condition for being a modal axiom. Nevertheless, she is free to exhibit similarities between various modal axioms, just as one might exhibit similarities between things that fall under our concept of a game, to use Wittgenstein’s example. Doing this would help to show that the Humean concept of necessity is not utterly arbitrary or heterogeneous.’ This no doubt helps the plausibility of Sider’s account in a way, but may also play into the hands of an objector, as we shall soon see.
This completes our exposition of Sider’s theory. In the next post we will consider some objections.
References
Merricks, Trenton (2013). Three Comments on Writing the Book of the World. Analysis 73 (4):722-736.
Sider, Theodore (2003). Reductive theories of modality. In Michael J. Loux & Dean W. Zimmerman
Sider, Theodore (2011). Writing the Book of the World. Oxford University Press.
(eds.), The Oxford Handbook of Metaphysics. Oxford University Press 180-208.
Sider, Theodore (2013). Symposium on Writing the Book of the World. Analysis 73 (4):751-770.
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